Cholesterol Drug Confusion: Is the Cancer Risk Real?

Health.com

September 04, 2008

THURSDAY, Sept. 4 (Health.com) — The news hit this week that a cholesterol-lowering drug called Vytorin was linked to a possible risk of cancer. If you’re one of millions of Americans who take a cholesterol-lowering drug—and possibly even unsure which type you are taking—you may be concerned.

So what is Vytorin? You’re probably familiar with the drug from TV ads (you get your cholesterol from your Grandma Barbie and barbecued ribs). Check out this YouTube video for a refresher or see our previous blog for a picture. If you don’t remember seeing one of those ads lately, it’s because they stopped running.

Vytorin’s troubles started in January, when a study found that the drug—a combination of a new medication, ezetimibe, and an older statin drug, simvastatin (Zocor)—was no more effective than simvastatin alone for treating patients with high cholesterol.

Although the difference was not statistically significant, patients treated with the pricier Vytorin had more narrowing of the arteries than the group treated with Zocor, which is sold in a cheaper generic form.

It’s not like other cholesterol drugsVytorin is not like other cholesterol-lowering drugs. It’s a relatively new way of lowering cholesterol that was first approved by the Food and Drug Administration (FDA) in 2004. (Ezetimibe on its own is sold under the name Zetia, which was first approved in 2002.)

Vytorin lowers LDL, or bad, cholesterol by blocking its absorption in the intestines, while other drugs work in different ways. So Vytorin’s issues don’t necessarily apply to other classes of drugs.

Researchers are concerned about Vytorin right now because study results released in July had an unexpected finding. Known as the SEAS trial, it looked at whether Vytorin could reduce heart attack, strokes, and heart-valve surgery in 1,873 people with aortic stenosis. It didn’t. However, they also found that Vytorin-treated patients seemed to have a greater risk of getting certain cancers—such as prostate, gastrointestinal, and skin cancers—than those treated with a placebo.

In response, the FDA announced it was taking a closer look at the drug. And a group of researchers at Oxford University analyzed early data from a couple of other big studies (20,000 patients, combined), called SHARP and IMPROVE-IT, which are ongoing.

While there were slightly more cancer deaths in the Vytorin-treated patients in these two trials, it was not statistically significant and most likely due to chance, according to the report in The New England Journal of Medicine. However, other experts are not so sure. When data from all three trials are combined, it looks like there may be a real increase in cancer mortality.

So that means the jury is still out on the issue. The results were not strong enough to halt the trial and the FDA did not remove the drug from the market, notes Gordon F. Tomaselli, MD, a Johns Hopkins University professor of medicine, and program chair of scientific sessions for the American Heart Association.

“I still think there’s a signal there, and I think it’s a signal we need to pay very careful attention to,” says Dr. Tomaselli. “I certainly don’t think it should stop patients who are in the two other trials from being in those trials, or from enrolling new patients.”

Fewer people taking Vytorin than in the pastDon’t know what drug you’re taking? Don’t be embarrassed, it’s not uncommon. But it’s probably not Vytorin.

In the United States, the “vast majority [of heart patients] are taking statins and statins alone,” says Douglas Zipes, MD, past president of the American College of Cardiology, and a distinguished professor at Indiana University School of Medicine in Indianapolis.

Statins include drugs such as Lipitor, Zocor, and Crestor. Other cholesterol-lowering, non-statin drugs include niacin, a type of vitamin, and fenofibrate, which is a fibric-acid derivative.

In the past, cancer-risk questions were raised about statins too. But an analysis of long-term data from 90,000 patients found it wasn't true.

And when statins debuted more than a decade ago, it was feared they might raise the risk of suicide or mental instability, because cholesterol is important for normal brain function, says Dr. Zipes. Those fears didn't turn out to be true, either.

Statins now have a long safety record (though some people have to stop taking them due to muscle aches). In fact, it has been suggested in recent year that statins are safe enough to be sold without a prescription, although that hasn’t happened yet.

”It was felt that statins were so safe that indeed they should go over-the-counter,” says Dr. Zipes.

It is possible that future research will show that Vytorin is no more likely to cause cancer than statins or any other drug. However, experts don’t really have enough information at this point to say one way or another.

“It’s not entirely settled by all of the data,” says Dr. Zipes. It’s been raised as a “very important issue but it has to be addressed more prospectively,” he says.

If you are taking VytorinGiven the attention to the drug this year, it’s not surprising that sales have slumped; you’re probably less likely to be prescribed this drug if you have high cholesterol.

“It’s dropped off significantly,” says Dr. Zipes. “Many of the cardiologists with whom I interact are no longer prescribing it.”

If you are taking Vytorin, your course of action depends on why you were given the drug, says Dr. Tomaselli. He says most patients with elevated cholesterol should be given a statin first, and if that doesn’t do the trick, they should try a higher dose of statins.

If they can't tolerate higher doses of statins, and need a different type of medication, there are many other options besides Vytorin, including niacin and fibrates.

“I would say to those folks, for the time being, if you’re on Vytorin for the reason of intolerance to higher-dose statins and/or failing to get to target on other drugs, then they should just stay on the drug for now,” he says.

Dr. Zipes also says, “There may be reasons why Vytorin might be used in a very small percentage of people.”

If you are taking the drug, experts recommend—as always—that you consult your doctor and don’t decide to stop taking it on your own.

“The number of deaths of coronary artery disease and stroke will be far greater if people stop their [medication] than if they continue on Vytorin in my opinion," says Dr. Tomaselli.